In recent years, much attention has been paid on reusing various types of products in order to conserve energy. Paper sheets and other printing media are no exception. Efforts have been made to reuse them.
For example, for recycling of paper sheets after printing of images thereon by printers, etc., processing of maceration, dust removal, etc. is carried out to form a used paper pulp, which is blended with new pulp to create new paper sheets. However, such reuse method has a high cost, and is relatively high in energy cost.
On the other hand, there is also a technology whereby the ink, toner, or other image forming substance on the printed media is “erased” by being de-colored or cleaned off so that the image is erased, and the print media can be reused. However, it is believed that according to this method, the print media degrades in the de-coloring or cleaning step.